JPS63500373A - Method and apparatus for producing spherical particles, and particles produced thereby - Google Patents

Abstract

(57) [Summary] This bulletin contains application data before electronic filing, so abstract data is not recorded.

Description

[Detailed description of the invention] Method and apparatus for producing spherical particles, and particles produced thereby Background of the invention The present invention relates to a novel method and apparatus for manufacturing spheres, particularly those made of glass or other spheres. Method and apparatus for manufacturing spheres from fine particles of building material, and objects manufactured thereby Concerning spheres.

Glass beads and other spherical particles made in accordance with the present invention are used in many industrial and commercial applications. It has commercial use.

In many cases, these beads are used for highway and local road lane markings, advertising signs, and Used to provide reflective surfaces such as picture screens. Other uses for these beads In the process, beads are used as a filler in plastic materials for impact treatment and pinpoint treatment of metal surfaces. their reflective properties, such as when used for lighting or various electrical applications. There are also less important uses. The diameter of the beads can vary widely, e.g. It ranges from about 6.0 millimeters to about 1 micron.

Various methods and apparatus have been used to produce glass spheres. example For example, its upper end is open and a moderately distributed gas flame is placed adjacent to its lower end. Irregularly shaped glasses are placed in upright draft pipes that are adjacent to each other. It has been common practice to supply particles with Particles are moved upward by combustion gases It is carried into an expansion chamber or chimney mounted above the draft pipe. particles are above During the transfer, it softens and becomes essentially spherical due to surface tension, forming a glass Becomes speed. A typical bead manufacturing method of this type will be explained in more detail. For example, on November 16, 1943, Rudolf H. U.S. Patent No. 2,334°578 issued to H. Potters No., United States Special Grant to Rudolph H. Potters on December 2, 1952. No. 2,619,776, July 19, 1960, by Tootus K. Wood ( U.S. Patent No. 2,945.32 granted to Thomas K., Wood) 6 and on February 1, 1971, Arthur G. U.S. Patent No. 3,560,185 issued to G. Nylander and No. 3,560,186.

In other examples, glass spheres were produced, for example, on October 18, 1966 by - As shown in fraudulent U.S. Pat. No. 3,279,905 to Wood et al. , have been manufactured directly from a stream of molten glass. Furthermore, it has been used Another method for producing spheres is to use a rotary kiln. These latter methods , resin or other binder and graphite etc. are added to the crushed glass particles. of material is conventionally coated to form a sphere and at the same time provide protection around each particle. Coating and/or Ma) IJ Lux is provided. This latter method was introduced in 19718. Charles Davidoff on March 3rd No. 3,597.177, issued February 8, 1949; U.S. patent number granted to Bru Taylor (N, W, Taylor), etc. No. 2,461,011.

Conventional methods and equipment used to produce spherical particles such as glass peas showed a disadvantage. For example, the overall thermal efficiency of many such conventional methods is relatively low and This resulted in an increase in the manufacturing cost of products. Additionally, this means that the upright draft pipe Of particular importance in methods and apparatus using Thermal efficiency is further compromised as some of the available energy must be used In some cases, this temperature gradient inside the tube may cause the shortcomings of the pond, which lacks roundness. This resulted in the production of spheres with of interparticle collisions that reduce product quality. It is necessary to carefully control the particle density to minimize generation. It is essential. The equipment used earlier to make glass spheres was large and further reduces the possibility of producing spheres efficiently and economically in continuous mass production. It had another drawback.

Other conventional methods and devices, such as those utilizing rotary kilns and similar equipment The coating used must be heated in addition to the protective coating binder or particles. It has the disadvantage of not requiring a significant amount of matrix either. Ta. Yet another drawback of this latter method and apparatus is that in order to obtain a coating-free product, , the coating must be removed by expensive mechanical methods such as cleaning. It was.

Summary of the invention It is therefore an object of the present invention to provide a novel method for producing glass beads or other spherical particles. The object of the present invention is to provide an economical method and apparatus.

More specifically, it is an object of the present invention to describe the method by which available heat has been achieved to date. It is an object of the present invention to provide the above method and apparatus which can be used more efficiently and economically.

Another object of the invention is that the particles obtained have very good homogeneity and roundness properties. An object of the present invention is to provide a method and apparatus for producing spherical particles.

Yet another object of the invention is to provide an extremely thin and uniform coating on the binder or matrix. To provide a method and apparatus for producing particles in which particles are coated without using a chemical. It is in.

Still another object of the invention is that the coating comprises: for producing optically transparent particles; Production of particles with the above characteristics that are removed without washing or mechanically removing the coating An object of the present invention is to provide a method and apparatus.

Still another object of the invention is to provide a novel modification that is economical and reliable in operation. The purpose of the present invention is to provide an improved method for manufacturing glass beads.

In one exemplary embodiment of the invention, a quantity of ground glass particles is fed into a fluidized bath. be done. An inert gas or other fluidizing medium is introduced into the fluidized bath to bring the particles into a fluidized state. do. The particles are then brought to a high enough temperature that the particles form into spheres due to surface tension. Get heated. The particles are then kept in a fluid state for a period of time sufficient to solidify the particles into a spherical shape. cooling while continuing.

Many preferred embodiments of the invention use a fluidized bed to produce or process the particles. This is a particularly advantageous feature of the new embodiment. Fluidized beds have never been used commercially. to confine the particles to a much narrower area than in most sphere manufacturing methods. As a result, the amount of heat loss during particle spheronization is significantly reduced. moreover, More uniform heat distribution in the fluidized bed enables the production of spheres with improved roundness and particle size properties do.

According to still other features of the invention, in some advantageous embodiments the particles are By the time they reach their softening temperature, a thin coat of protective material is applied. particles are spheres If they come into contact with each other while being formed, the coating will cause the particles to clump together or otherwise This will help prevent it from gluing if you don't have it. The coating is installed in an upright draft pipe or a rotary - Even in the kiln method, it is preferable that the particles be made of oxidizable carbon that adheres to the particles.

According to still further features in some preferred embodiments of the invention, after spheronization, the coating The particles are exposed to an oxidizing atmosphere. The particles are optically transparent and the resulting spheres are optically transparent. The coating is removed by burning or oxidizing so that it has strong and good retroreflection properties. It is kept in this atmosphere for a long enough time.

The invention and further objects and features will be described in the following preferred embodiments with reference to the accompanying drawings. It will be more clearly and completely understood from the description of the embodiments.

Brief description of the drawing FIG. 1 is a schematic diagram of a method and apparatus for manufacturing glass beads according to an exemplary embodiment of the present invention. It is a schematic diagram.

FIG. 2 shows the method and apparatus utilized in FIG. 1 taken along line 2-2 of FIG. FIG.

FIG. 3 is a cross-sectional view taken along line 3--3 of FIG.

3a is a horizontal cross-sectional view taken along line 3a-3a of FIG. 2. FIG.

FIG. 4 is a cross-sectional view of another fluidized vessel utilized in the method and apparatus of FIG. 1.

FIG. 5 is a horizontal cross-sectional view taken along line 5--5 of FIG.

FIG. 6 is a longitudinal sectional view of a third fluidized tank utilized in the method and apparatus of FIG. 1.

FIG. 7 is a cross-sectional view taken along line 7--7 of FIG.

FIG. 8 shows a method and apparatus for manufacturing glass beads according to another exemplary embodiment of the present invention. FIG. 3 is a cross-sectional view of the fluidized tank used.

FIG. 9 is a horizontal cross-sectional view taken along line 9--9 of FIG. 8.

Description of preferred embodiments Referring to Figure 1 of the attached drawings, glass beads are made from finely ground glass particles. A method and apparatus for manufacturing is shown. In an exemplary embodiment, the crushed Although the particles consist of conventional soda lime-silicate glass, the method and apparatus of the present invention may be caused by surface tension or other Spheres can also be made from almost any fine material that has the property of becoming spherical by some means. It can be used with almost equal ease to produce whole bodies. shown in the drawing The method and apparatus produce large quantities of glass beads by using one or more fluidized vessels. It is particularly useful for producing However, as explained in more detail below, , some features of the invention may be used in upright draft pipes, rotary kilns or other types of It can also be applied to the production of beads using beads production equipment.

In the method and apparatus of FIG. is continuously supplied to the tumbler 10. The tumbler 10 has a normal shape, A supply conduit 12 is also provided for containing a suitable dressing. This covering material is shown below. Advantageously, it is an oxidizable and adherent carbonaceous material of the type described in more detail. Ru. This coating material is thoroughly mixed with the glass particles in the tumbler 10, so that each particle is Provides a very thin but complete coating. The binder or matrix is this mixture Although not added to the This contributes to achieving a smooth and uniform coating.

The thus coated glass particles are passed from the tumbler 10 through a conduit 13 and a valve 14. and enters a sphere-forming container in the form of a fluidized tank 15. Best shown in Figures 2 and 3. As shown, the conduit 16 is located on the left side of the upper wall 19 of the fluidization tank, adjacent to the feed end. It enters the fluidized tank 15. A lower wall 20. Vertical side M22 and 23 and horizontal side wall 2 5 and 26 as well. Each of these is made of fire-resistant insulation. child These walls form a longitudinally extending rectangular container that houses the various internal elements of the fluidized tank. has been completed.

Two elongated and relatively narrow partition chambers 60 and 61 are provided within the fluidization tank 15. There is. These nine compartments 60 and 61 are connected to the covered glass from the particle supply conduit 16. are arranged parallel to each other in position to receive the particles. conduit 16 have branch conduits 13a and 13b' communicating with the partition chambers 60 and 61, respectively, at their lower ends. A Y-shaped joint is provided so as to form an e-formation. The compartments 30 and 61 have a series of doors. A baffle plate 62 is provided respectively (Fig. 3a). It is in the form of a vertical plate located in a plane transverse to the longitudinal direction, and along the partition Extending alternately from both sides of the compartment to provide a tortuous flow path for the moving particles. It is growing.

Heating zones 36, 37 and 68 are provided within fluidized tank 15. These heating zones The temperature of the zones is controlled separately by heating elements 39, 40 and 41 in the fluidized tank 15. Ru. As best shown in FIGS. 3 and 3a, heating elements 39 and 41 are provided adjacent each vertical side wall 22 and 23 of fluidized tank 15, while heating element 40 is It is provided in the center between the two partition chambers 60 and 610. The fluidized tank 15 is below It further has a discharge zone 45 provided at the flow or discharge end. This emission band 45 is an upright weir plate extending across each partition 60 and 31. It is separated from heating zone 38 by 46.

An adjustable weir plate 47 connects the discharge zone 45 and the lateral side wall 26 at the discharge end of the fluidized vessel 15. is interposed between. The weir plate 47 has a central opening formed by the horizontal edge 48. In the discharge conduit 49 which is provided and extends through the lower wall 20 of the fluidization tank 15. is slidably placed for vertical movement. This discharge conduit is suitable for It communicates with the compartments 30 and 61 of the fluidization tank 15 by mold connections (not shown). ing. The weir plate 47 is attached to the conduit 49 to change the position of the edge 48 within the conduit. It can be moved either upwards or downwards.

A bottom plate 51 with holes is supported in the fluidizing tank 15 at a distance above the bottom wall 20. Five Two gas supply conduits 53, 54, 55, 56 and 57 penetrate the bottom wall 2o of the fluidization tank 15. extending through and spaced along the longitudinal center of the fluidization tank. Ru. These supply conduits extend into the space between the bottom wall 26 and the bottom plate 51 and then through the holes in the bottom plate. arranged for introducing fluidizing gas into the two internal compartments 60 and 61 through the ing.

Referring again to FIG. 1, fluidizing gas is introduced into the system through supply conduit 60. Ru. The gas reacts with nitrogen or the coating material or particles to be spheronized at the temperatures used in the system. Advantageously, the other gas is sufficiently inert that it does not. The introduced gas is supplied by the supply valve. 62 and a blower 66 to the heat exchanger 65. From the heat exchanger 65, the flow The oxidizing gas enters a preheater 67 and then heaters 69 and 70 arranged in series. be n.

Conduit 72 is connected to supply conduit 60 between heaters 67 and 690. Branch conduit 7 2 extends into two valves 76 and 74 located parallel to each other, and these valves n connection to gas supply conduits 53 and 54, respectively.

A second branch conduit 76 is connected to conduit 60 between heaters 69 and 70. branch guide Pipe 76 extends through valve 77 to gas supply conduit 55 . Remaining gas supply conduit 56 and 57 are connected to conduit 60 by a branch conduit 78 downstream of heater 70 . The flow of fluidizing gas fL through heater 70 and branch conduit 78 is controlled by valve 79. It will be done.

The fluidizing gas in conduit 60 is preheated by heat exchanger 65 and preheater 67 and then A portion of the preheated gas flows through branch conduit 72 and gas supply conduits 56 and 54. It is arranged so as to be introduced into the heating zone 36 of the tank 15. Preheated fluidized gas Other parts of the gas supply are further heated by a heater 69 to provide a branch conduit 76 and a gas supply. It is introduced via conduit 55 into heating zone 67 of fluidized tank 15 . −10,000, preheated flow A third portion of the oxidizing gas is further heated by heater 70 and sent to branch conduit 78 and gas. The gas is introduced into the heating zone 68 and discharge zone 45 of the fluidized tank via supply conduits 56 and 57. It will be done.

Upstream side of the upper wall 19 (FIG. 2) for continuous collection of inert gas into the fluidized tank 15 A gas exhaust conduit 80 is provided adjacent the end. The discharge conduit 80 is from the fluidization tank 15. A service that helps separate all dirt and other fine materials from incoming hot inert gases. It is connected to the Ikron separator 84. Fine material is passed through valve 82 and return conduit 85. and return it to the fluidization tank 15. - 10,000, the recovered gas passes through conduit 87 and into conduit 60. Directed to a heat exchanger 65 used to partially preheat the fresh inert gas . Cooling water is supplied to the recovered gas from the heat exchanger 65 through the entire conduit 92. The process proceeds to the cooling device 90.

The cooled gas is then injected into the backwash nitrogen supply conduit 96 and any remaining gas It enters a back filter having a collection chamber 97 for collecting fine materials. The conduit 99 Gas is guided from the filter 95 to another filter 100. This latter The filter is connected to supply conduit 60 by conduit 102 between valve 62 and blower 66. It is connected. The thus cooled and filtered gas flows into the conduit 60 as a fresh stream. mixed with chemical gas and circulated within the system.

Conduit 106 is connected to fluidizing gas conduit 60 by valve 104 . conduit 10 3 is connected to the conduit between the heat exchanger 65 and the preheater 67, and is connected to the conduit from the discharge conduit 49. for supplying fluidizing gas to the intermediate fluidizing tank 105 containing the coated glass spheres; used for. The fluidized tank 105 is a counter for isolating the inert atmosphere inside the fluidized tank 15. It acts as a soil fluidizing tank and also partially cools the sphere. From the discharge pipe 49 In order to ensure a free flow n of fluid falling into the fluidization tank 105, the fluidization tank is connected to the pump 10. 8 and a discharge conduit 106 leading to a separator 84. Pump 108 is a fluidized tank Inert gas is continuously drawn out from 105 to prevent excessive pressure in the fluidized tank. I'm here.

From the fluidized tank 105 for sealing and intercooling, the coated spheres are passed through a discharge conduit 107. Proceed to oxidation fluidized tank 110. As best shown in Figures 4 and 5, The fluidized tank 110 has a casing 11 of refractory insulation surrounding a cylindrical shell 116. Consists of 2. Shell #113 is a bottom plate with holes spaced apart on the bottom wall of the casing 112. It has 114. An air supply conduit 115 directs the fluidizing gas between the bottom wall and the bottom plate 114. penetrate the bottom wall of the casing to insert into the space between, and then through the holes in the bottom plate. In turn, 9 maintains the coated sphere within shell 116 in a fluid state of an oxidizing atmosphere.

The shell 116 serves as a container for the coated sphere and has an exhaust vent extending upwardly from the top of the shell. It has a conduit 116.

The fluidized tank 110 receives a supply of air or other oxidizing gas from a supply conduit 120 (FIG. 1). receive. The supplied gas passes through the air filter 121 and the blower 122 to the valve 1. 24 and then passes through heater 126 to supply conduit 115.

The fluidized particles exiting the fluidized tank 110 pass through conduit 128 to a cooling station generally indicated at 130. be discharged into a fluidized tank.

As best shown in FIG. It consists of a rectangular metal casing 162 surrounded by 64. Jacket 164 is supplied with water or other cooling fluid through supply conduit 165 and is provided with cooling flow. The body is drained through drain conduit 136. The perforated plate 168 is attached to the casing 162. It is placed on the bottom with a small gap. The valve 14 is placed in the space under the perforated plate 168. 2 (FIG. 1) to the supply conduit 120 between the blower 122 and the valve 124. Air or other fluidizing gas at room temperature is supplied from a supply conduit 169 which is located in the air. flow The oxidizing gas is passed through an exhaust pipe 144 that communicates with the exhaust pipe 116 coming out of the oxidizing fluidized tank 110. is continuously discharged from the cooling fluidized tank.

The irregularly shaped particles introduced into Memplar 10 may be made of glass or other various materials. It consists of In addition to the soda-lime glass used for highway lane markings, e.g. Glasses with high refractive index such as tan glass can be used with virtually the same ease. Ru. These particles may be screened to limit the product to a specific size range if desired. can also be used to form glass spheres of various sizes on them. processed according to the method of the present invention, and then optionally whole beads of a particular size range. Can be screened for delivery.

The method of the present invention can be applied to plastics or other materials that can be softened when heat is applied. Spheres can be made from almost any material. One advantage of this method is that Can produce spheres with larger diameters than many methods used commercially to date. It is possible. For example, in the conventional upright draft back system, the diameter of the sphere is Generally ranges from about 1 micron up to about 1.0 mm, but the present invention By this method, good quality spheres are formed and these are coated with a grain size of about 1 micron to about 6.0 mm. It has a diameter in the range of about 1.5 mm.

Irregularly shaped particles are oxidizable and adhere to extremely fine particle sizes in tumbler 10. Mix thoroughly with the protective coating. A wide variety of covering materials can be used that meet these criteria. However, particularly good results are achieved with coatings consisting of carbon black.

wetted by boron nitride, silanes with carbon atoms and softened or molten glass Other carbonaceous materials can also be used with good results. As a covering material Useful carbon blacks are classified as commercially available furnace blacks. There are some.

The coating material used is sufficient to provide a complete and uniform coating around each glass particle. It should be the amount. However, even if excess coating material is applied to the particles, the excess This material does not improve the effectiveness of the coating and is simply wasted. American standard 18-4 Crushed glass in the particle size range of 0 mesh and previously used carbon brass For bulk materials, an amount of coating material of 9 to 1 bond per particle (approximately 0.45?) is preferred. The weight should be about 0.5 grams to about 2 grams; particularly good results are obtained when the coating The material is applied at a rate of approximately 1.0 grams per particle (approximately 0.45 to 5'). This will be achieved if Approximately 0.5 grams or less per bond (approximately 0.45 to 2) In most cases, the material is insufficient to completely cover each particle, while 1 bond (approximately 0.4 Approximately 2 grams per 5 to 5') or more will yield a satisfactory product, but excess coating material yields no more useful results. For particles smaller than 18-40 meshes In this case, a proportionately larger amount of coating material is used since the surface area of the particles is increased. this In contrast, particles above this particle range require considerably less coating material. a The amount of coating material used in a particular experiment is approximately linearly and inversely proportional to the particle surface area. . To meet these criteria, the amount of coating applied to the glass particles should be approximately 0.1 % to about 0.5% by weight.

The use of adhesive coatings with this property means that binders and matrices are added to the coating. Achieves smooth and uniform coating on each particle without using wax or other additives. That will happen. Therefore, resin, charcoal matrix, etc. are eliminated, resulting in a coating It will be applied more quickly and less expensively than traditional dressings.

Upon completion of the coating process, the crushed glass particles are passed through conduit 16 to fluidized bath 15. be introduced. The flow rate of the introduced particles is determined by the flow rate of the fluidized tank partitions 30 and 31 (Fig. i3). and Fig. 3a), particles in an amount approximately half the volume of each compartment are continuously retained. That's about it. The particles enter the inert gas in conduits 53, 54, 55, 56 and 57. Therefore, while the particles are fluidized in the partition chambers 60 and 61 and are in a fluidized state, the particles high temperature and time sufficient to soften the particles and cause them to form into spheres due to surface tension. heated up to.

As the particles move through successive zones 66, 37, 38 and 45 of the fluidized tank 15, Particle heating is carefully controlled by adjusting the temperature of the inert atmosphere within each zone. be controlled. This includes external heaters 67.69 and 7o and internal heaters 39.40 and 7o. and 41 (FIGS. 3 and 3a). For example, For a powder lime silicate glass, the temperature of the particles moving through the heating zone 66 is approximately 4 00°C.

At this stage of the method, particles are not softened and a uniform carbonaceous coating is maintained. I have it. In the heating zone 67, the particle temperature [14] is again raised and heated. In zone 38 and discharge zone 45, the particle temperature increases to about 850°C or 900°C. be raised further. The residence time in the two zones 38 and 45 maintains the fluid state. Each particle is softened while being heated, and the particles can be formed into a spherical shape by the surface tension of the particles. For example, 15 minutes is sufficient to make the process work. Atmosphere within zones 38 and 45 is sufficiently inert to prevent any combustion or oxidation of the coating on the particles. conduit 5 The inert gas supplied from 5 is maintained at a temperature of about 600°C by a heater 69. , and heater 70 together with heaters 39, 40 and 41 (FIGS. 3 and 3a). The temperature of the atmosphere in zones 38 and 45 is further increased to bring the particles to their spheroidization temperature. make it happen.

The fluidized particles in the fluidized tank 15 are It is held at the spheroidization temperature. As best shown in FIG. The height of the particles inside is considerably lower due to the weir plate 46, and the height of the particles is lowered. It passes over one edge 48 of the plate 47 into an upright discharge conduit 49.

From the discharge conduit 49 these spherical particles enter a fluidized tank 105 for sealing and intercooling. . The temperature of the particles is rapidly lowered in the fluidized bath 105, and the temperature is sufficiently lowered to fix them in a spherical shape. It is maintained in a flowing state for a period of time at a reduced temperature of, for example, 600°C. In addition to particle cooling, In addition, the fluidized tank 105 has an inert atmosphere in the fluidized tank 15 and an oxidizing atmosphere in the fluidized tank 110. Provides a seal with the surrounding air.

When exposing the fixed spherical particles to the oxidizing atmosphere in the fluidized tank 110, the carbon on the particles The raw cladding material burns rapidly and is exhausted through exhaust pipe 116. The coating is as described above. As it is very thin, the coating on each particle is removed from the surface of the spherical particle and its The result is that each sphere is optically clear and requires no further cleaning, washing or other treatment. stomach. The oxidizing atmosphere in the fluidized tank 110 is at a temperature exceeding the combustion or oxidation temperature of the coating material. However, if the spheres come into contact with each other after the coating has been removed, the spheres will adhere or deform. The temperature should be below the softening temperature of the spherical particles to avoid it. Atmosphere inside fluidized tank 110 is heated and exposed by heated air entering the fluidized tank through heater 126 and conduit 115. This temperature is maintained by the heat generated by the combustion of the covering material.

The optically clear glass spheres pass through conduit 128 to cooling fluidized bath 160 . spherical The particles are maintained in a fluidized state in a fluidized bath 160, during which time their temperature is approximately 90°. It is further lowered to C. The resulting product is then discharged to collector 148.

During the manufacturing process of the present invention, both the particles and the coating material are dried in the absence of water or other liquids. in a state of The presence of water in the tumbler 10 can cause particles to adhere to each other, for example. tend to increase the amount of coating material used on each particle. . At the temperatures encountered in the fluidized bath 15, the water produces oxygen and as a result some of the coating material parts may burn prematurely. Since the particles come into contact with each other in a fluid state, the particles In order to avoid adhesion or deformation of the coating until the particles have fixed in the shape of the glass sphere, It is important that the material remains on each particle. Next, the covering material is heated while the sphere is still hot. removed from the sphere while in

8 and 9, in accordance with another exemplary embodiment of the present invention. A fluidized tank 150 is shown containing a quantity of ground particles to be spheronized. Fluidization tank 1 50 is a casing 152 made of a fire-resistant heat insulating material and a cylindrical shell inside the casing. It is equipped with 153. The perforated bottom plate 154 is separated from the bottom wall of the casing 152 and It is provided in the well 156. Nitrogen supply conduit 60 (Figure 1) or heated inert gas A supply conduit 155 projects through the bottom wall and is connected to a suitable supply source in the pond. ing. Conduit 155 passes through the space between the bottom wall and bottom plate 154 and then through the hole in the bottom plate. and enter the gas to maintain the crushed particles in the shell 153 in a fluidized state in an inert atmosphere. do. The shell continuously withdraws inert gas from the shell and transfers that gas to the above It also has a return conduit 156 for circulation into the system.

A particle supply conduit 158 extends through the cylindrical side wall of shell 153 and is connected to the burner. -160 is located externally adjacent the shell. The burner exhaust system is The entire conduit 161 connected tangentially at the bottom of the shell 156 connects to the inside of the shell 156. I understand. A fuel-rich flame is maintained in the burner 160 and the burner exhaust It produces soot in the form of carbon black.

Once the crushed glass particles are introduced into shell 156 through conduit 158, they They are made fluid by the inert gas coming in through conduit 155. burner When carbon black entering the shell 156 from the exhaust pipe 161 of the The carbon black flows along a swirling or spiral flow path, creating a thin but complete coating. onto each glass particle within the well. The flame of the burner is carbonated at the above rate. Adjusted to introduce racks.

While the particles are in a fluidized state in the fluidized tank, the coated particles in the fluidized tank 150 The tension heats it to a high enough temperature that it becomes spherical. The particles then harden into spherical shapes. The coating is cooled in a fluid state for a sufficient period of time to allow the coating to be oxidized by the oxidation method described above. removed.

The present invention is particularly useful in the production of glass spheres by using one or more fluidized vessels. Although illustrated and described as such, certain features of the present invention may also be used with other sphere manufacturing methods. You can do it. For example, the novel coating and coating removal techniques described herein Fut tube method, rotary kiln, so-called frying technology, and drip granulation or injection When used in the production of spheres by injection granulation tower, it becomes a more efficient method and practical. This results in a qualitatively improved product. The coating is made of these various types of particles. It prevents deformation and adhesion, and the spherical particles can be easily removed without cleaning. The resulting product shows very good homogeneity and contains a very high proportion of true spheres. I'm reading. The present invention can be used in a variety of other sphere manufacturing or processing schemes, including: It will be apparent to those skilled in the art upon reading the above specification.

The terms and expressions used are for descriptive purposes only and are not intended to be limiting. and exclude any equivalents or parts of the features illustrated and described. It is not our intention to use such terms and expressions in order to Various modifications can be made to the present invention. It is acknowledged that it is possible within the scope of the claims.

FIG. 4 FIG, 6 FIG, 7 FIG, 8 FIG, 9 international search report ----＾eplka+1oIIN&PCT/US86101109

Claims (23)

[Claims] (1) A method for producing spheres from a large number of fine particles, the method comprising: a step of introducing a fluidizing medium into the fluidizing tank to suspend the particles; Fluidizing the particles; While in the fluidized state in the fluidized bath, the surface tension of the particles is sufficient to cause them to become spherical. heating the particles to an elevated temperature; The particles are kept in a fluid state for a period of time sufficient to fix them into a spherical shape. A method consisting of a combination of steps for cooling spherical particles. (2) A method for producing spheres from a large number of fine particles, the method including producing a large number of particles in a fluidized bath. a step of introducing a fluidizing gas into the fluidizing tank to suspend the particles; Fluidizing the particles; Heat is applied to the fluidizing gas to increase the surface tension of the particles while they are in a fluidized state in the fluidizing tank. raising the temperature of said particles to a height sufficient to cause them to become spherical by force; , cooling the spherical particles while maintaining them in a fluid state for a sufficient period of time to solidify them into a spherical shape. A method consisting of a combination of steps. (3) the fluidizing gas is continuously drawn from the fluidizing tank; A method according to claim 2, as recited in . (4) A method for producing a sphere from a large number of fine particles, the method comprising: introducing the fluidizing medium into the first fluidizing tank, and introducing the particles into the first fluidizing tank; a step of floating the particles to fluidize the particles, and bringing the particles into a fluid state in the first fluidization tank. The particles are heated to a high enough temperature during which time they form into spheres due to surface tension. a heating process; The particles are kept in a fluidized state for a sufficient period of time to fix them into a spherical shape in a second fluidized bath. A method consisting of a combination of a moving process. (5) A method for producing spheres from a large number of fine particles, the particles being coated with a protective coating. and introducing the particles into a fluidized tank. A process for fluidizing the particles by introducing a fluidizing gas into the fluidizing tank and suspending the particles. With mode, While the particles are in a fluidized state in the fluidized tank, the particles are formed into a spherical shape due to surface tension. heating the particles to a sufficiently high temperature; The spherical particles are cooled while being maintained in a fluid state for a sufficient period of time to fix them into a spherical shape. and removing the coating from the spherical particles. (6) A method for manufacturing spheres from a large number of fine particles, wherein the oxidizable protective material is and introducing the coated particles into a sphere manufacturing container. heating the particles to a temperature high enough to make them spherical; thereafter cooling the particles for a sufficient period of time to solidify the particles into a spherical shape; A combination with a step of exposing the sphere to an oxidizing atmosphere to oxidize and remove the coating. A method consisting of (7) A method for producing spheres from a large number of fine particles, the method comprising from about 0.1% by weight to about 0% by weight. ．． coating the particles with an oxidizable and adhesive protective material within a range of 5% by weight; , introducing the coated particles into a sphere production container having an inert atmosphere; heating the particles to a temperature high enough to cause them to become spherical due to surface tension; With mode, thereafter cooling the particles for a sufficient period of time to solidify the particles into a spherical shape; A process of completely removing the coating from the spherical particles by oxidizing the coating. A method consisting of a combination of processes. (8) A method for producing glass spheres from glass fine particles, comprising: coating the glass particles with an oxidizable and adhesive protective material; introducing the coated particles into a sphere production container having an inert atmosphere; heating the particles to a temperature high enough to spheroidize them while in the container; process and then cooling the particles for a sufficient period of time to solidify them into a spherical shape; A combination with a step of exposing the sphere to an oxidizing atmosphere to oxidize and remove the coating. A method consisting of (9) Claims in which the oxidizable and adhesive protective material is made of carbon black. The method described in box 7. (10) The oxidizable and adhesive protective material tags the mixture of the protective material and the particles. 9. A method according to claim 8, wherein the method is coated by embedding. (11) supplying a fuel-rich flame and discharging the combustion products of the flame into the particles; forming a coating of the oxidizable and adhesive protective material on the particles; 9. The method of claim 8 further comprising a combination of. (12) A method for producing spheres from a large number of fine particles, which are oxidizable and adhesive. Coating the particles with a protective material; introducing the coated particles into a first fluidized tank; Introducing an inert gas into the first fluidization tank to suspend the particles and fluidize the particles. The particles are formed into spheres by surface tension while in the fluidized state in the first fluidized tank. heating the particles to a temperature high enough to form before entering a second fluidized bath which keeps the particles in a fluidized state for a sufficient period of time to solidify them into a spherical shape. a step of moving the particles; A method comprising the step of removing the coating from the spherical particles. (13) A method for producing glass spheres from glass fine particles, comprising: coating the glass particles with an oxidizable and adhesive protective material; introducing the coated particles into a first fluidized tank having an inert atmosphere; While the particles are in a fluidized state in the first fluidized tank, they become spherical due to surface tension. heating the particles to a sufficiently high temperature; Cooling the particles while maintaining them in a fluid state for a sufficient period of time to solidify them into a spherical shape. process and The particles are kept in a fluid state for a sufficient period of time to oxidize and completely remove the protective coating on them. a step of moving the particles to a second fluidized tank having an oxidizing atmosphere, where the particles are A method consisting of combinations. (14) The oxidizable and adhesive protective material comprises carbon black. The method according to scope item 13. (15) A method for producing glass spheres from glass fine particles, comprising: coating the glass particles with an oxidizable and adhesive protective material; introducing the coated particles into a first fluidized tank having an inert atmosphere; While the particles are in a fluidized state in the first fluidized tank, they become spherical due to surface tension. heating the particles to a sufficiently high temperature; Cooling the particles while keeping them in a fluid state for a period of time sufficient to solidify them into a spherical shape. The particles are kept in a fluid state for a sufficient period of time to oxidize and remove the protective coating on them. The fluidized particles are transferred to a second fluidized tank having an oxidizing atmosphere, where the fluidized particles are maintained in a step and then move the particles to a third fluidized bath to further cool the particles. A method consisting of a combination of a process of (16) A sphere manufactured by the method according to claim 1. (17) A sphere manufactured by the method according to claim 6. (18) A sphere manufactured by the method according to claim 15. (19) A device for manufacturing spheres from a large number of fine particles, which accommodates a large number of the particles. a first fluidized tank for suspending and fluidizing the particles in the fluidized tank; means for introducing a fluidizing gas into a fluidized tank, the particles being exposed while in a fluidized state in said fluidized tank; heating means for raising the temperature of said particles to a height sufficient to cause them to become spherical due to surface tension; as well as said spherical particles while maintaining the particles in a fluid state for a sufficient time to solidify into a spherical shape. device consisting of a combination of means for cooling (20) An apparatus for manufacturing spheres from a large number of fine particles, wherein the oxidizable protective material is means for coating particles; a fluidized tank containing said coated particles; and fluidizing said particles. means for introducing an inert gas into the fluidized tank to While in the fluidized state in the fluidized bath, the surface tension of the particles is sufficient to cause them to become spherical. heating means for raising the temperature of said particles to a height; The spherical particles are cooled while being maintained in a fluid state for a sufficient period of time to fix them into a spherical shape. and cooperating with said fluidized bath to completely remove the protective coating from said spherical particles. device consisting of a combination of the same means. (21) Collect inert gas from the fluidized tank and transfer the recovered gas to the fluidized tank. 21. Apparatus according to claim 20, further comprising means for returning for circulation. (22) An apparatus for producing glass spheres from glass fine particles, comprising: means for coating a number of said glass particles with an oxidizable and adhesive protective material; a first fluidization tank containing the coated particles, for fluidizing the particles therein; means for introducing an inert gas into the first fluidized tank; While the particles are in a fluidized state in the first fluidized tank, the surface tension is sufficient to cause the particles to become spherical. heating means for raising the temperature of said particles to a height of Cooling the spherical particles while maintaining them in a fluid state for a sufficient period of time to solidify them into a spherical shape. means to a second fluidized tank having an oxidizing atmosphere, and from said first fluidized tank, particles are deposited thereon; before being held in a fluid state for a sufficient period of time to oxidize and remove the applied protective coating. means for moving the spherical particles to the second fluidized tank. (23) An apparatus for producing glass spheres from glass fine particles, A tumbler in which a large number of the glass particles are coated with an oxidizable and adhesive protective material. a first fluidized tank containing the coated particles; a first fluidized tank containing the coated particles; means for introducing an inert gas into the first fluidization tank; While the particles are in a fluidized state in the first fluidized tank, they become spherical due to surface tension. heating means for raising the temperature of said particles to a sufficient height; the spherical particles while maintaining the particles in a fluid state for a sufficient period of time to solidify into a spherical shape. means for cooling, a second fluidized tank with an oxidizing atmosphere; The particles from the first fluidized bath oxidize and completely remove the protective coating thereon. the spherical particles in the second fluidized bath where they are held in a fluidized state for a sufficient period of time to means of moving; a third fluidized tank, and from said second fluidized bath before being held in a fluidized state for a sufficient period of time for further cooling. means for moving the spherical particles to the third fluidized tank.